Measurement of Plasma Formed by High-Speed Impact to Estimate Temperature at Impact Point

2019 ◽  
pp. 335-342
Author(s):  
Y. Motoyama ◽  
K. Umeda ◽  
T. Sakai ◽  
S. Kinoshita ◽  
K. Watanabe
Keyword(s):  
High Speed ◽  
Impact Point ◽  
High Speed Impact

scholarly journals Energy Absorption Characteristics of PVC Coarse Aggregate Concrete under Impact Load

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Shi Hu ◽  
Huaming Tang ◽  
Shenyao Han
Keyword(s):  
Compressive Strength ◽  
Energy Absorption ◽  
High Speed ◽  
Coarse Aggregate ◽  
Specific Energy Absorption ◽  
Low Speed ◽  
High Speed Impact ◽  
Aggregate Content ◽  
Dynamic Compressive Strength ◽  
Absorption Characteristics

AbstractIn this paper, polyvinyl chloride (PVC) coarse aggregate with different mixing contents is used to solve the problems of plastic pollution, low energy absorption capacity and poor damage integrity, which provides an important reference for PVC plastic concrete used in the initial support structures of highway tunnels and coal mine roadway. At the same time, the energy absorption characteristics and their relationship under different impact loads are studied, which provides an important reference for predicting the energy absorption characteristics of concrete under other PVC aggregate content or higher impact speed. This study replaced natural coarse aggregate in concrete with different contents and equal volume of well-graded flaky PVC particles obtained by crushing PVC soft board. Also, slump, compression, and splitting strength tests, a free falling low-speed impact test of steel balls and a high-speed impact compression test of split Hopkinson pressure bar (SHPB) were carried out. Results demonstrate that the static and dynamic compressive strength decreases substantially, and the elastic modulus and slump decrease slowly with the increase of the mixing amount of PVC aggregate (0–30%). However, the energy absorption rate under low-speed impact and the specific energy absorption per MPa under high-speed impact increase obviously, indicating that the energy absorption capacity is significantly enhanced. Regardless of the mixing amount of PVC aggregate, greater strain rate can significantly enhance the dynamic compressive strength and the specific energy absorption per MPa. After the uniaxial compression test or the SHPB impact test, the relative integrity of the specimen is positively correlated with the mixing amount of PVC aggregate. In addition, the specimens are seriously damaged with the increase of the impact strain rate. When the PVC aggregate content is 20%, the compressive strength and splitting strength of concrete are 33.8 MPa and 3.26 MPa, respectively, the slump is 165 mm, the energy absorption rate under low-speed impact is 89.5%, the dynamic compressive strength under 0.65 Mpa impact air pressure is 58.77 mpa, and the specific energy absorption value per MPa is 13.33, which meets the requirements of shotcrete used in tunnel, roadway support and other impact loads. There is a linear relationship between the energy absorption characteristics under low-speed impact and high-speed impact. The greater the impact pressure, the larger the slope of the fitting straight line. The slope and intercept of the fitting line also show a good linear relationship with the increase of impact pressure. The conclusions can be used to predict the energy absorption characteristics under different PVC aggregate content or higher-speed impact pressure, which can provide important reference for safer, more economical, and environmental protection engineering structure design.

Investigation on the mechanical properties of press-hardened boron steel sheets using the conductive heating technique

2020 ◽  
Vol 234 (8) ◽  
pp. 1084-1098
Author(s):  
O Kocar ◽  
H Livatyalı
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Boron Steel ◽  
Fast Heating ◽  
Heating Method ◽  
Conductive Heating ◽  
Press Hardening ◽  
High Speed Impact ◽  
Significant Difference ◽  
Structural Parts

An aluminized 22MnB5 (Boron) steel sheet, used for structural parts in the automotive industry, was subjected to press-hardening followed by austenitizing, both in a conventional furnace and via the conductive (electric resistance) heating method, an innovative technique based on the Joule’s principle for fast heating of the sheet metal. Conductive heating presents a number of advantages over the in-furnace heating method. These include a more efficient use of energy, as well as the requirement of less time and space for heating, thus lowering costs. After press-hardening was performed using both methods, the microstructural and mechanical characterizations of both specimens were examined for optical microscopy, hardness, tensile strength, and high-speed impact tests. The results showed that the press-hardening process transformed the ferritic–pearlitic microstructure in the as-received state into martensite after die quenching and caused a substantial increase in hardness and strength at the expense of ductility and impact toughness. On the other hand, no significant difference was observed in either the microstructure or mechanical properties with respect to the heating method used. The results obtained in the present investigation concur with the findings of current literature.

High Speed Impact Behaviour of Thermo-Mechanically Processed AA 6082-T6 Thin Plates

2018 ◽  
Vol 5 (9) ◽  
pp. 17203-17212 ◽  
Author(s):  
Rahul Dubey ◽  
Srinivasa Rakesh ◽  
R Velmurugan ◽  
R Jayaganthan
Keyword(s):  
High Speed ◽  
Thin Plates ◽  
Impact Behaviour ◽  
High Speed Impact

Interfacial structure in TiB2/Al composite after high speed impact

Micron ◽  
2012 ◽  
Vol 43 (5) ◽  
pp. 688-693 ◽  
Author(s):  
Q. Guo ◽  
D.L. Sun ◽  
L.T. Jiang ◽  
G.H. Wu ◽  
X.L. Han
Keyword(s):  
High Speed ◽  
Interfacial Structure ◽  
High Speed Impact ◽  
Al Composite

Fuel Leaking Analysis of Fuel Tank by Projectiles Impact with Mechanical Properties of Projectiles

2013 ◽  
Vol 644 ◽  
pp. 203-206
Author(s):  
Hai Liang Cai ◽  
Bi Feng Song ◽  
Yang Pei ◽  
Shuai Shi
Keyword(s):  
High Speed ◽  
Drop Size ◽  
Fuel Tank ◽  
Size Distributions ◽  
Sauter Mean Diameter ◽  
Fuel Droplets ◽  
High Speed Impact ◽  
Fuel Tanks ◽  
Rigid Projectile ◽  
Drop Size Distributions

For making sure the dry bay ignition and fire, it’s necessary to calculate the number and the sizes of the droplets and determine the mass flow rate of the fuel induced by high-speed impact and penetration of a rigid projectile into fuel tank. An analytical model is founded and the method for calculating the initial leaking velocity of the fuel is determined. It gives the equation for calculating the drop size distributions of fuel and the Sauter mean diameter (SMD) of droplets, through the Maximum Entropy Theory and the conservation for mass. Using the Harmon’s equation for SMD,the fuel droplets SMD can be calculated. Results shows that the initial leaking velocity of the fuel is about linearly increasing with the velocity of the projectile, the SMD of fuel droplets increases with the hole size of the fuel tank which induced by the penetration of the projectile and linearly decreases with the velocity of the projectile. The results can be used for the ignition and fire analysis of the dry bay adjacent to fuel tanks.

Experimental Calibration of ISV Damage Model Constants for Pure Copper for High-Speed Impact Simulation

2016 ◽  
Author(s):  
Yangqing Dou ◽  
Yucheng Liu ◽  
Wilburn Whittington ◽  
Jonathan Miller
Keyword(s):  
High Speed ◽  
Impact Analysis ◽  
Split Hopkinson Pressure Bar ◽  
Internal State ◽  
Pure Copper ◽  
Damage Model ◽  
Hopkinson Pressure Bar ◽  
Experimental Calibration ◽  
High Speed Impact ◽  
The Impact

Coefficients and constants of a microstructure-based internal state variable (ISV) plasticity damage model for pure copper have been calibrated and used for damage modeling and simulation. Experimental stress-strain curves obtained from Cu samples at different strain rate and temperature levels provide a benchmark for the calibration work. Instron quasi-static tester and split-Hopkinson pressure bar are used to obtain low-to-high strain rates. Calibration process and techniques are described in this paper. The calibrated material model is used for high-speed impact analysis to predict the impact properties of Cu. In the numerical impact scenario, a 100 mm by 100 mm Cu plate with a thickness of 10 mm will be penetrated by a 50 mm-long Ni rod with a diameter of 10mm. The thickness of 10 mm was selected for the Cu plate so that the Ni-Cu penetration through the thickness can be well observed through the simulations and the effects of the ductility of Cu on its plasticity deformation during the penetration can be displayed. Also, that thickness had been used by some researchers when investigating penetration mechanics of other materials. Therefore the penetration resistance of Cu can be compared to that of other metallic materials based on the simulation results obtained from this study. Through this study, the efficiency of this ISV model in simulating high-speed impact process is verified. Functions and roles of each of material constant in that model are also demonstrated.

Damage evolution behavior of TiN/Ti multilayer coatings under high-speed impact conditions

2021 ◽  
pp. 127807
Author(s):  
Zhanwei Yuan ◽  
Yutao Han ◽  
Shunlai Zang ◽  
Jiao Chen ◽  
Guangyu He ◽  
...  
Keyword(s):  
Damage Evolution ◽  
High Speed ◽  
Multilayer Coatings ◽  
High Speed Impact ◽  
Evolution Behavior

Calculation of Transparent Armor Resistance to a High-Speed Impact by a Spherical Projectile

2021 ◽  
Vol 47 (2) ◽  
pp. 130-134
Author(s):  
A. N. Ishchenko ◽  
S. A. Afanas’eva ◽  
N. N. Belov ◽  
V. V. Burkin ◽  
A. S. D’yachkovskii ◽  
...  
Keyword(s):  
High Speed ◽  
High Speed Impact ◽  
Transparent Armor
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